Telephonic transmitter



(No Model.) 2 SheetsSheet 1.

J. H. GUEST. TELEPHONIG TRANSMITTER.

Patented Feb. 10, 1885.

N PETERS. PhoXa-Lllhugmphur. Washmglnn. D. c

(No Model.) 2 SheetsSheet 2.

J H. GUEST.

TELBPHONIO TRANSMITTER.

No. 311,979. Patented Feb. 10, 1885.

llNtTED STATES PATENT OFFICE.

JOHN H. GUEST, OF BROOKLYN, NEW YORK.

TELEPHONIC TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 311,979, dated February 10, 1885.

' Application filed September 18, 1882. Renewed July 11, 18-4. (No model.)

To on whom it may concern:

Be it known that I, JOHN H. GUEsT, of Brooklyn, in the county of Kings and State of New York, have invented an Improvement in Telephonic Transmitters, of which the following is a specification.

I have discovered that the peculiar properties of glass are such that it is better adapted to form the diaphragm and the inclosing-case for the electrodes than any other material, because the whole is made of one uniform material without joints, so that the electrodes are protected from the atmospheric changes, and the angles and ofi'sets,which are liable to produce a false sound or echo, are entirely avoided. I adjust the bearing of one electrode upon the other by the action of ascrew outside the glass, and I sometimes mount the glass in bearings or trunnions, so that it may be partially rotated in effecting the adjustment.

In the drawings, Figure 1 is a vertical section of the telephone-instrument and its protecting-boX. Fig. 2 is also a sectional view representing a modification in the details of the devices' 3 shows one of the trunnions in section. Fig. 4 is a detached view showing the electrodes after the glass case has been tipped. Figs. 5 and 6 are sections of the glass case, with a lever and adjusting-screw, and Fig. 7 is a plan of the adjusting-lever shown in Fig. 5.

The diaphragm a and the other portion, b c, of the case are of glass blown and shaped in any usual manner. It is preferable to have a flat or nearly flat diaphragm, and one of the electrodes, (Z, is fastened thereto, and the other electrode, e, is loose. The portion 0 of the case contains mercury, which floats the carbon or other electrode, 0, into contact with the electrode d. This feature of an electrode floated by mercury is shown in a prior application, and is not, therefore, claimed herein. The rodf,upon which the electrode (2 is held, is preferably secured permanently into the glass at the center of the diaphragm, as shown, and one of the circuit-wires may be attached to its outer end, as shown by dotted lines; but I prefer to connect the circuit-wire 2 Within the glass vessel, and carry it out through one of the hollow trunnions, h. The

other circuit-wire, 3, is in the mercury in c,

and passes out through the glass in any convenient manner.

1 It is to be understood that after the glass vessel has been blown and shaped at the diaphragm a hole should be opened in the middle and the electrode d and wire f inserted, and then the glass is closed around the wire f by melting the glass. The electrode 6 can be inserted previous to the insertion of the electrode d. The electrode and glass may be connected in any suitable manner. One of the trunnions h is to be left open until after the mercury has been poured in. The quantity introduced is to be sufficient to float the electrode e'into contact with or close proximity to the electrode d, as may be required, according to the mode of adjustment hereinafter set forth. The air may now be exhausted from the glass vessel and the trunnion hermetically sealed, or some gas may be introduced that will not injure the electrodes in the presence of an electric spark.

I remark that I prefer and use carbon electrodes; but I do not limit myself in this particular.

In order to vary the pressure upon the electrodes in adjusting the instrument, I combine with the glass case a screw to give motion to such glass case, or aport-ion thereof. I usually' mount the said glass telephonic-transmitter case in a box, Z, of wood or other material, having a mouth-piece, s, the trunnions h hav .ing hearings therein, and I use the screw m to swing the glass case into an inclined position. When the diaphragm is horizontal, the mercury will usually act with its greatest force in floating the electrode e,- but if .the case is swung to an inclination the electrode d as sumes an inclined position to the electrode 6, as seen in Fig. 4, and the mercury partially spreads in the portion a, and the electrode a is not so deeply immersed; hence the contactpressure between (1 e is lessened. By varying the shape of the mercury-holder the pressure will be increased when the case is inclined. The same effect is produced upon the electrodes by adjusting the case by the screw in when the electrode d is fastened upon or nearer to the interior of the diaphragm a, as seen in Fig. 2, and the electrode 6 is suspended and hangs by gravity with more or less force against the electrode d, according to the position into ICO which the case is, swung upon its trunnionsh by the action of the screw m. In this instance the nut 0, which the screw acts upon, is rep resented as hollow at one side to receive the contractedend of the glass case and move the same and turn the glass. case on itstrunnions h. If the nut is turned so that the point of suspension of the electrode 0 is moved to the right,the electrode will hang with more pressure against the electrode d, and the pressure will be lessened by the point of suspension being swung to the left. I am also enabled to adjust the pressure of the electrodes on each other within the glass vessel by the action of the screw outside such vessel by applying the screw to. regulate the pressure of a spring, 1*,

(shown by dotted lines in Fig. 1,) such spring bearing upon the diaphragm near the center, the glass being sufficiently thin and elastic to allow of the small movement required in this adjustment.

the screw m to move the mercury-holder c and the electrode 6 toward or from the electrode d.

In Fig. -5 the screw m is shown as acting upon a lever, 19, in which is fastened the. circuit-wire 3, and the glass is slightly drawn down to lessen the pressure on the electrodes, and the reverse. In Fig. 6 the lever and screw are applied so as to spring the glass by pressure upon the lower part, c, the upper part being supported" by the ledge 12. This glass case for the electrodes of the telephonic transmitter, on account of its continuous homogeneous structure,insures great clearness at the receiving-instrument, and the receiver is to a remarkable extent freefrom false sounds and irregularities in the tone, indicating that the electric pulsations correctly correspond to the sound-waves in the atmosphere. A slide and clamp or a cam or wedge may be used for adjusting and holding the parts, in place of the screw.

I claim as my invention 1. The combination, with the electrodes and circuit-connections in a telephonic transmitter, of an inclosing glass case, a portion of which forms the dlaphragm, substantially as set forth.

2. The combination, with the electrodes and circuit-connections in a. telephonic transmitter, of a diaphragm and, case of glass, and a screw or its equivalent outside such case to adjust the pressure of the electrodes, substan- J. H. GUEST.

Witnesses:

CLINTON M. BALL, DE 13. WILMOT. 

